1 files changed, 429 insertions, 0 deletions

diff --git a/src/core/core.c b/src/core/core.c
new file mode 100644
index 0000000..90038c6
--- /dev/null
+++ b/src/core/core.c
@@ -0,0 +1,429 @@
+#include "core_impl.h"
+
+#include "gl_util.h"
+
+// #include <log/log.h>
+
+#include <assert.h>
+
+void gfx_init_gfxcore(GfxCore* gfxcore) {
+  assert(gfxcore);
+
+  mempool_make(&gfxcore->buffers);
+  mempool_make(&gfxcore->framebuffers);
+  mempool_make(&gfxcore->geometries);
+  mempool_make(&gfxcore->renderbuffers);
+  mempool_make(&gfxcore->shaders);
+  mempool_make(&gfxcore->shader_programs);
+  mempool_make(&gfxcore->textures);
+
+  mempool_make(&gfxcore->shader_cache);
+  mempool_make(&gfxcore->program_cache);
+
+  glEnable(GL_CULL_FACE);
+  glFrontFace(GL_CCW);
+  glCullFace(GL_BACK);
+
+  glEnable(GL_DEPTH_TEST);
+
+  // Filter cubemaps across their faces to avoid seams.
+  // https://www.khronos.org/opengl/wiki/Cubemap_Texture#Seamless_cubemap
+  glEnable(GL_TEXTURE_CUBE_MAP_SEAMLESS);
+}
+
+// Conveniently destroy any objects that have not been destroyed by the
+// application.
+void gfx_del_gfxcore(GfxCore* gfxcore) {
+  assert(gfxcore);
+
+  mempool_foreach(&gfxcore->buffers, buffer, { gfx_del_buffer(buffer); });
+
+  mempool_foreach(&gfxcore->framebuffers, framebuffer, {
+    gfx_del_framebuffer(framebuffer);
+  });
+
+  mempool_foreach(
+      &gfxcore->geometries, geometry, { gfx_del_geometry(geometry); });
+
+  mempool_foreach(&gfxcore->renderbuffers, renderbuffer, {
+    gfx_del_renderbuffer(renderbuffer);
+  });
+
+  mempool_foreach(
+      &gfxcore->shader_programs, prog, { gfx_del_shader_program(prog); });
+
+  mempool_foreach(&gfxcore->shaders, shader, { gfx_del_shader(shader); });
+
+  mempool_foreach(&gfxcore->textures, texture, { gfx_del_texture(texture); });
+}
+
+// -----------------------------------------------------------------------------
+// Render commands.
+// -----------------------------------------------------------------------------
+
+void gfx_start_frame(GfxCore* gfxcore) {
+  assert(gfxcore);
+
+  glViewport(
+      gfxcore->viewport.x, gfxcore->viewport.y, gfxcore->viewport.width,
+      gfxcore->viewport.height);
+  glClearColor(0, 0, 0, 0);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+  ASSERT_GL;
+}
+
+void gfx_end_frame(GfxCore* gfxcore) {
+  assert(gfxcore);
+  ASSERT_GL;
+}
+
+void gfx_set_viewport(GfxCore* gfxcore, int x, int y, int width, int height) {
+  assert(gfxcore);
+  gfxcore->viewport =
+      (Viewport){.x = x, .y = y, .width = width, .height = height};
+}
+
+void gfx_get_viewport(
+    GfxCore* gfxcore, int* x, int* y, int* width, int* height) {
+  assert(gfxcore);
+  assert(x);
+  assert(y);
+  assert(width);
+  assert(height);
+
+  *x      = gfxcore->viewport.x;
+  *y      = gfxcore->viewport.y;
+  *width  = gfxcore->viewport.width;
+  *height = gfxcore->viewport.height;
+}
+
+void gfx_clear(GfxCore* gfxcore, vec4 colour) {
+  assert(gfxcore);
+
+  glClearColor(colour.x, colour.y, colour.z, colour.w);
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+}
+
+void gfx_set_blending(GfxCore* gfxcore, bool enable) {
+  assert(gfxcore);
+  if (enable) {
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+  } else {
+    glDisable(GL_BLEND);
+  }
+}
+
+void gfx_set_depth_mask(GfxCore* gfxcore, bool enable) {
+  assert(gfxcore);
+  glDepthMask(enable ? GL_TRUE : GL_FALSE);
+}
+
+void gfx_set_culling(GfxCore* gfxcore, bool enable) {
+  assert(gfxcore);
+  if (enable) {
+    glEnable(GL_CULL_FACE);
+  } else {
+    glDisable(GL_CULL_FACE);
+  }
+}
+
+void gfx_set_polygon_offset(GfxCore* gfxcore, float scale, float bias) {
+  assert(gfxcore);
+  if ((scale != 0.0f) || (bias != 0.0f)) {
+    glEnable(GL_POLYGON_OFFSET_FILL);
+  } else {
+    glDisable(GL_POLYGON_OFFSET_FILL);
+  }
+  glPolygonOffset(scale, bias);
+}
+
+void gfx_reset_polygon_offset(GfxCore* gfxcore) {
+  assert(gfxcore);
+  glPolygonOffset(0, 0);
+  glDisable(GL_POLYGON_OFFSET_FILL);
+}
+
+// -----------------------------------------------------------------------------
+// Buffers.
+// -----------------------------------------------------------------------------
+
+Buffer* gfx_make_buffer(GfxCore* gfxcore, const BufferDesc* desc) {
+  assert(gfxcore);
+  assert(desc);
+
+  Buffer* buffer = mempool_alloc(&gfxcore->buffers);
+  if (!gfx_init_buffer(buffer, desc)) {
+    mempool_free(&gfxcore->buffers, &buffer);
+    return 0;
+  }
+  return buffer;
+}
+
+void gfx_destroy_buffer(GfxCore* gfxcore, Buffer** buffer) {
+  assert(gfxcore);
+  assert(buffer);
+  if (*buffer) {
+    gfx_del_buffer(*buffer);
+    mempool_free(&gfxcore->buffers, buffer);
+  }
+}
+
+// -----------------------------------------------------------------------------
+// Geometry.
+// -----------------------------------------------------------------------------
+
+Geometry* gfx_make_geometry(GfxCore* gfxcore, const GeometryDesc* desc) {
+  assert(gfxcore);
+  assert(desc);
+
+  Geometry* geometry = mempool_alloc(&gfxcore->geometries);
+  if (!gfx_init_geometry(geometry, gfxcore, desc)) {
+    mempool_free(&gfxcore->geometries, &geometry);
+    return 0;
+  }
+  return geometry;
+}
+
+void gfx_destroy_geometry(GfxCore* gfxcore, Geometry** geometry) {
+  assert(gfxcore);
+  assert(geometry);
+
+  if (*geometry) {
+    gfx_del_geometry(*geometry);
+    mempool_free(&gfxcore->geometries, geometry);
+  }
+}
+
+// -----------------------------------------------------------------------------
+// Textures.
+// -----------------------------------------------------------------------------
+
+Texture* gfx_make_texture(GfxCore* gfxcore, const TextureDesc* desc) {
+  assert(gfxcore);
+  assert(desc);
+
+  Texture* texture = mempool_alloc(&gfxcore->textures);
+  if (!gfx_init_texture(texture, desc)) {
+    mempool_free(&gfxcore->textures, &texture);
+    return 0;
+  }
+  return texture;
+}
+
+void gfx_destroy_texture(GfxCore* gfxcore, Texture** texture) {
+  assert(gfxcore);
+  assert(texture);
+  assert(*texture);
+
+  if (*texture) {
+    gfx_del_texture(*texture);
+    mempool_free(&gfxcore->textures, texture);
+  }
+}
+
+// -----------------------------------------------------------------------------
+// Renderbuffers.
+// -----------------------------------------------------------------------------
+
+RenderBuffer* gfx_make_renderbuffer(
+    GfxCore* gfxcore, const RenderBufferDesc* desc) {
+  assert(gfxcore);
+  assert(desc);
+
+  RenderBuffer* renderbuffer = mempool_alloc(&gfxcore->renderbuffers);
+  if (!gfx_init_renderbuffer(renderbuffer, desc)) {
+    mempool_free(&gfxcore->renderbuffers, &renderbuffer);
+  }
+  return renderbuffer;
+}
+
+void gfx_destroy_renderbuffer(GfxCore* gfxcore, RenderBuffer** renderbuffer) {
+  assert(gfxcore);
+  assert(renderbuffer);
+  assert(*renderbuffer);
+
+  if (*renderbuffer) {
+    gfx_del_renderbuffer(*renderbuffer);
+    mempool_free(&gfxcore->renderbuffers, renderbuffer);
+  }
+}
+
+// -----------------------------------------------------------------------------
+// Framebuffers.
+// -----------------------------------------------------------------------------
+
+FrameBuffer* gfx_make_framebuffer(
+    GfxCore* gfxcore, const FrameBufferDesc* desc) {
+  assert(gfxcore);
+  assert(desc);
+
+  FrameBuffer* framebuffer = mempool_alloc(&gfxcore->framebuffers);
+  if (!gfx_init_framebuffer(framebuffer, desc)) {
+    mempool_free(&gfxcore->framebuffers, &framebuffer);
+    return 0;
+  }
+  return framebuffer;
+}
+
+void gfx_destroy_framebuffer(GfxCore* gfxcore, FrameBuffer** framebuffer) {
+  assert(gfxcore);
+  assert(framebuffer);
+  assert(*framebuffer);
+
+  if (*framebuffer) {
+    gfx_del_framebuffer(*framebuffer);
+    mempool_free(&gfxcore->framebuffers, framebuffer);
+  }
+}
+
+// -----------------------------------------------------------------------------
+// Shaders.
+// -----------------------------------------------------------------------------
+
+static uint64_t hash_shader_desc(const ShaderDesc* desc) {
+  assert(desc);
+  // Note that defines may affect shader permutations, so we need to hash those
+  // as well.
+  uint64_t hash = 0;
+  for (size_t i = 0; i < desc->num_defines; ++i) {
+    const ShaderCompilerDefine* define = &desc->defines[i];
+    hash = (((hash << 13) + sstring_hash(define->name)) << 7) +
+           sstring_hash(define->value);
+  }
+  return (hash << 17) + cstring_hash(desc->code);
+}
+
+static uint64_t hash_program_desc(const ShaderProgramDesc* desc) {
+  assert(desc);
+  return ((uint64_t)desc->vertex_shader->id << 32) |
+         (uint64_t)desc->fragment_shader->id;
+}
+
+static Shader* find_cached_shader(ShaderCache* cache, uint64_t hash) {
+  assert(cache);
+  mempool_foreach(cache, entry, {
+    if (entry->hash == hash) {
+      return entry->shader;
+    }
+  });
+  return 0;
+}
+
+static ShaderProgram* find_cached_program(ProgramCache* cache, uint64_t hash) {
+  assert(cache);
+  mempool_foreach(cache, entry, {
+    if (entry->hash == hash) {
+      return entry->program;
+    }
+  });
+  return 0;
+}
+
+static ShaderCacheEntry* find_shader_cache_entry(
+    ShaderCache* cache, const Shader* shader) {
+  assert(cache);
+  assert(shader);
+  mempool_foreach(cache, entry, {
+    if (entry->shader == shader) {
+      return entry;
+    }
+  });
+  return 0;
+}
+
+static ShaderProgramCacheEntry* find_program_cache_entry(
+    ProgramCache* cache, const ShaderProgram* prog) {
+  assert(cache);
+  assert(prog);
+  mempool_foreach(cache, entry, {
+    if (entry->program == prog) {
+      return entry;
+    }
+  });
+  return 0;
+}
+
+Shader* gfx_make_shader(GfxCore* gfxcore, const ShaderDesc* desc) {
+  assert(gfxcore);
+  assert(desc);
+
+  // Check the shader cache first.
+  ShaderCache*   cache  = &gfxcore->shader_cache;
+  const uint64_t hash   = hash_shader_desc(desc);
+  Shader*        shader = find_cached_shader(cache, hash);
+  if (shader) {
+    // LOGD("Found cached shader with hash [%lx]", hash);
+    return shader;
+  }
+
+  shader = mempool_alloc(&gfxcore->shaders);
+  if (!shader) {
+    return 0;
+  }
+  if (!gfx_compile_shader(shader, desc)) {
+    mempool_free(&gfxcore->shaders, &shader);
+    return 0;
+  }
+  ShaderCacheEntry* entry = mempool_alloc(cache);
+  *entry                  = (ShaderCacheEntry){.hash = hash, .shader = shader};
+  // LOGD("Added shader with hash [%lx] to cache", hash);
+  return shader;
+}
+
+void gfx_destroy_shader(GfxCore* gfxcore, Shader** shader) {
+  assert(gfxcore);
+  assert(shader);
+
+  if (*shader) {
+    // Remove the shader from the cache.
+    ShaderCache*      cache = &gfxcore->shader_cache;
+    ShaderCacheEntry* entry = find_shader_cache_entry(cache, *shader);
+    assert(entry); // Must be there, shaders can't go untracked.
+    mempool_free(cache, &entry);
+
+    gfx_del_shader(*shader);
+    mempool_free(&gfxcore->shaders, shader);
+  }
+}
+
+ShaderProgram* gfx_make_shader_program(
+    GfxCore* gfxcore, const ShaderProgramDesc* desc) {
+  assert(gfxcore);
+  assert(desc);
+
+  // Check the shader program cache first.
+  ProgramCache*  cache = &gfxcore->program_cache;
+  const uint64_t hash  = hash_program_desc(desc);
+  ShaderProgram* prog  = find_cached_program(cache, hash);
+  if (prog) {
+    // LOGD("Found cached shader program with hash [%lx]", hash);
+    return prog;
+  }
+
+  prog = mempool_alloc(&gfxcore->shader_programs);
+  if (!gfx_build_shader_program(prog, desc)) {
+    mempool_free(&gfxcore->shader_programs, &prog);
+    return 0;
+  }
+  ShaderProgramCacheEntry* entry = mempool_alloc(cache);
+  *entry = (ShaderProgramCacheEntry){.hash = hash, .program = prog};
+  // LOGD("Added shader program with hash [%lx] to cache", hash);
+  return prog;
+}
+
+void gfx_destroy_shader_program(GfxCore* gfxcore, ShaderProgram** prog) {
+  assert(gfxcore);
+  assert(prog);
+  if (*prog) {
+    // Remove the shader program from the cache.
+    ProgramCache*            cache = &gfxcore->program_cache;
+    ShaderProgramCacheEntry* entry = find_program_cache_entry(cache, *prog);
+    assert(entry); // Must be there, shaders can't go untracked.
+    mempool_free(cache, &entry);
+
+    gfx_del_shader_program(*prog);
+    mempool_free(&gfxcore->shader_programs, prog);
+  }
+}